The present invention relates to a dental measuring and machining system.
For producing a dental prosthesis such as an implant, inlay, bridge or crown, an apparatus, by which a suitable dental prosthesis is formed by preparing three-dimensional measurement data by measuring the shape of a model sampled from a defective part of the teeth or jaw and so forth, and machining a block of a material optimum for a prosthesis based on the measurement data, is proposed. This type of apparatus uses a computer for controlling the function for numerically encoding and computing data, and the function for driving a cutting drill based on this computed data to machine the block by grinding or cutting. Generalization and increased efficiency of the computer is realized under a practical level by the combination of general-purpose OS and CAD/CAM software, so that the apparatus can be operated easily even if a user does not have detailed and specialized knowledge in the fields of dentistry or machinery but can understand the manner of use to a certain extent. For example, an example of such an apparatus is Dental Measuring and Machining Apparatus xe2x80x9cCADIMxe2x80x9d (registered trademark) (made by Advance Corporation).
In this manner, even in the case of an apparatus by which a dental prosthesis can be produced with specialized dental knowledge as long as the manner of use can be understood to a certain extent, if the user does not fully understand the use of a computer, or if the user understands the use of a computer, it is required to deal with erroneous operations or rare cases, and the situation is unchanged so that the user must learn to the extent necessary to overcome such problems.
In addition, since there are individual differences in the shapes of defective parts of teeth or jaw shape and so forth, the prostheses are always forced to custom-made production, and automated mass production is unexpected, forcing them to be handled on a case-by-case basis.
Moreover, even if the computer has a high degree of universality and its operation is not that much different from the operation of routinely used personal computers, since a beginner still has to learn to operate the computer, and that operation has the special nature of measuring and machining dental prostheses, there are still cases in which specialized operations for adjusting software or additional information is required depending on the addition, revision or alteration of its functions.
Thus, although the support of a person having a certain degree of specialized knowledge is required for use, since there are many cases in which simply sending a document or a floppy disk to the user and having the user perform operation are not adequate, ultimately resulting in the need to dispatch a trainer to the user""s location, as the area covered expands, it becomes necessary to contend with a large burden in terms of both cost and labor in order to accommodate this situation.
Moreover, although contact measurement using a probe or non-contact measurement using an optical technique such as laser light are employed as methods for measuring the surface shape of a model obtained from the oral cavity of a patient in order to obtain an accurate prosthesis, the contact type is preferable in terms of seeking accuracy.
However, in the case of the contact type, since it is necessary to manipulate the probe so that is makes contact with the entire surface of the model, in addition to requiring considerable time, it is also necessary to rotate and move the model for that purpose.
In addition, since a conventional probe is composed in the shape of a single rod positioned horizontally on the so-called Z axis, and comes out at locations where measurement is difficult, it becomes necessary to change the position of the model more carefully.
This type of tedious manipulation requires a considerable amount of learning by the dentist and so forth that uses it. In addition, since the driving parts for moving the probe, the grinding tool and the cutting tool become large, this type of measuring and machining equipment takes up space, and there is a case in which its installation is difficult for a small-scale dental practitioner, etc.
Moreover, although computerized measuring and machining is useful in terms of simplifying the conventional, tedious machining process and reducing cost, on the other hand, the noise produced during machining by the machine tool portion for dental cutting results in a difficult situation for performing in parallel with dental treatment.
In addition, even if operation of the machinery for measuring and machining is premised on the use of a general-purpose computer, since it is necessary to learn how to operate the computer, the machinery cannot be used immediately.
In addition, although varying somewhat depending on the measurement technique, the amount of time spent on a series of measuring and machining takes about a half day even if the user is familiar with the operation.
In addition, since there are some prostheses that are made of pure titanium and so forth that cannot be machined by a general-purpose machine tool, there are limitations on the types of prostheses that can be machined.
Therefore, by separating the measuring section and machining section, and having the dentist, dental technician or other user retain only the measuring section, while installing the machining section at an external, specialized facility, together with reducing the burden on the user, various other advantages are obtained, including being able to produce all types of prostheses, and enabling the user to be freed from the noise of the machine tools.
However, in the case of transmitting data from the measuring machinery to the machining machinery, since dental prostheses inherently having defective parts of irregular shapes or have large shapes such as in the case of full implants, there are many cases in which a large amount of data is required. Consequently, a considerable amount of time ends up being required for transmitting all measurement data, thereby resulting in the problem high so-called secondary cost in the form of public telephone line connection cost, equipment investment cost and so forth.
In consideration of the above, the present invention enables sharing the information within a dental measuring and machining apparatus or bidirectionally transmittable conditions through a communication medium, and realizes the production of a prosthesis, that allows direct and practical distribution of a software for improving a measuring and machining function (version-up), maintenance of software, etc., consultation for persons performing similar measuring and machining as well as the provision, manipulation and handling of various other information considered to be beneficial, real-time customer management, and the receiving and placing of orders for blocks for prosthesis formation, other instruments and machinery, outside measuring or outside machining, while also enabling transmission and receiving operations on data for reproducing measuring and machining operations on the user side at a support side, to thereby fully demonstrate the inherent functions of the apparatus even if the user is a beginner.
An algorithm in the present invention refers to a program or data, which includes software, data and so forth relating to CAD/CAM software, NC software, a measuring section and machining section, including the general program for driving the equipment of the measuring section and machining section, or data obtained as a result of that, and data that contains the parameters for arbitrarily running the program, although not limited to those.
The outside in the present invention refers to a region other than a machinery and instrument that execute measuring and machining, and covers various locations from a broad range extending to both at home and abroad to a narrow range such as within the same room.
In another aspect of the present invention, the dental measuring and machining apparatus is provided with a probe having contacts that extends in the directions of a cross for contact measurement of the surface of a model for producing a prosthesis, surface shape acquisition means for obtaining the shape of the surface of the above model based on contact by the above probe, and machining means that performs machining processing by a cutting and grinding tool on a model for machining a prosthesis based on the data of the above surface shape acquisition means. As a result of having this constitution, the surface shape of the model can be adequately measured while minimizing movement of the model, thereby making it possible to reduce the burden on the user.
Moreover, the present invention realizes stable measurement of the surface shape of a model while holding a probe in a stable manner on which the weight burden is increased in a complex manner by using a parallel link structure for the drive unit that drives the probe, and while performing highly accurate operation extremely easily and enabling the overall size to be reduced.
Moreover, the present invention enables highly accurate models to be formed at high speed and without taking up space while also allowing the obtaining of highly accurate prostheses by employing a constitution in which the compact measuring section and the machining section are separated, data of the measuring section is transmitted to the outside, and the prosthesis is formed based on this transmitted data, and a constitution that combines a cross probe with a parallel link drive unit that drives it.
The cross probe in the present invention refers to a constitution in which, for example, contacts or so-called styluses are extended in the positive and negative directions of the X axis and Y axis centering about the Z axis within three-dimensional coordinates.
Each of the contacts, in addition to presenting a rod shape extending linearly, may also be formed into a curves shape or composed in the shape of an acute angle.
Although the example of the contacts shows a vibrating type provided with a vibrator composed of a piezoelectric material that vibrates a vibrator at the site where the contact is connected, and a detector also composed of a piezoelectric material that detects changes in the resulting vibrations when the contact has contacted a model, there are also cases in which other techniques are used.
Preferable examples of this cross-type probe can be referred to in the technologies described in Japanese Unexamined Patent Publication No. 10-47941 and Japanese Unexamined Patent Publication No. 10-176902.
The parallel link structure in the present invention is preferably used by, for example, a so-called robot manipulator as described in the Journal of the Japan Robot Society, Vol. 10 (1992) pp. 757-763.
A parallel link has a composition in which, for example, both ends of two sets each of a total of six serial link drivers, which extend and contract by the driving of a linear motor, are connected in parallel at three locations on a drive side support plate and support base (Stewart platform type), or a composition of a three-shaft or six-shaft type, and has a composition in which a potentiometer, which obtains angle information and other positional information of a so-called joint section composed on the link end, is respectively connected to each drive side support plate on the driving end side.
A parallel link allows high-speed movement simply by driving the motor of each drive member to expand and contract, and has an extremely simple composition. In addition, since a parallel link drives as a result of being supplemented by a plurality of driving parts, it is suitable for driving heavy objects, and in addition to being able to be used preferably in the case of using a cross-type probe having a complex structure and being somewhat heavy as in the present invention, since control of the parallel link can be performed simply by controlling the motor, it is capable of performing extremely high-speed movement of the probe.
Although preferable examples of the composition of a parallel link can be referred to in the technologies described in Japanese Unexamined Patent Publication No. 5-138560 and Japanese Unexamined Patent Publication No. 8-281581, the composition is not limited to these, but rather is only required to have a composition in which driving members are linked in so-called parallel. Furthermore, since a three-shaft type of parallel link is composed by only using three serial links, it is preferable in terms of costs.
In still another aspect of the present invention, it has been made possible to produce a dental prosthesis that is capable of withstanding prosthetics by extracting data of its characteristic site and then performing supplementary work. In this manner, since only data of the characteristic site is required to be sent, shortening of transmission time can be realized, thereby realizing a system that does not place a burden on users.
The characteristic site in the present invention, in the case of a crown for example, indicates three pieces of data consisting of data on the occlusal surface of the model for producing the prosthesis, data on the site from the occlusal surface to the maximum lateral projection, and data on the contact line between the abutment and crown (margin line), or data on sections of the prosthesis having sudden projections, or data indicating the oral cavity environment such as height, width and so forth during occlusion in the case of partial or full dentures.
More specifically, since the neck is obtained numerically from the sum of the margin and projection, the characteristic site consists of margin line data and projection line data, and this portion is transmitted.
Since the cement space and coping shape are obtained numerically from the abutment surface, the portion of the abutment surface data is transmitted as the characteristic site.
Furthermore, since the abutment surface data is also obtained from the apex and bottom line data, only this portion may also be transmitted as characteristic section data. Since intraconal crown shape data and other double crown data and so forth are also obtained numerically from margin line data, conus angle data and conus height data, margin line data, conus angle data and conus height data may also be transmitted as characteristic sections.
Supplementary work refers to supplementing missing shape data obtained with characteristic site data and parameters with straight lines, planes, curved lines and curved planes. Bezier, spline and other curve processing means are used as specific supplementation techniques.
There are cases in which prostheses produced on the basis of this degree of transmission data are superior to prostheses produced by transmitting all data in terms of compatibility, stress diffusion and durability.